Field of the Invention
The present invention relates to an image processing apparatus, an image processing method and a program.
Description of the Related Art
In general, an imaging apparatus such as a digital camera has an automatic white balance controlling function of automatically adjusting the color tone of a photographed image. According to conventional automatic white balance control, a calculated white balance correction value is applied to an entire image. Hence, in the case of photographing in an environment in which plural light sources exist (for example, photographing with strobe light-emitting), it is difficult to obtain an image having coloring appropriate to each of the light sources.
To deal with this, for example, an electronic still camera described in Japanese Patent No. 3540485 compares an image at photographing with strobe light-emitting and an image at photographing without strobe light-emitting for each arbitrary object region to obtain the ratio of data, and determines the degree of contribution of strobe light based on the value of the obtained ratio. Then, according to the degree of contribution, the electronic still camera described in Japanese Patent No. 3540485 selects a white balance correction value for each region of image data obtained by emitting strobe light for light exposure, to thereby perform white balance control.
Unfortunately, in the case of the technique described in Japanese Patent No. 3540485, there is a time difference in acquisition timing between image data photographed with strobe light-emitting and image data photographed without strobe light-emitting. Hence, the electronic still camera described in Japanese Patent No. 3540485 has a problem that, for example, in the case where one of an object and a camera is moving, the radiation range and the radiation amount of strobe light are erroneously detected and a coloring discrepancy occurs in a boundary portion of a substance such as the object. Moreover, the electronic still camera described in Japanese Patent No. 3540485 performs development processing after varying a white balance correction value for each region. Hence, other controls such as color reproduction control may not be appropriate to the white balance correction value. As a result, appropriate coloring cannot be sufficiently reproduced.